Dynamo-armature



(No Model.)

0. O. C. BILLBERG.

"DYNAMO ARMATURE.

No. 401,632. Patented Apr. 16, 1889.

FIG/.1.

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CARL O. O. BILLBERG, OF PHILADELPHIA, ASSIGNOR TO THOMAS H. DALLETT. AND GEORGE A. DALLEIT, OF THORNBURY, PENNSYLVANIA.

DYNAMO-ARMATU RE.

SPECIFICATION forming part of Letters Patent No. 401,632, dated April 16, 1889.

Application filed October 1, 1888. Serial No. 286,816. (No model.)

To all whom it may concern eddy-currents and consequent heating of the Be it known that I, CARL O. O. BILLBERG, core in the field-magnet could be gotten rid of. a subject of the King of Sweden, residing at My present invention consists of a means Philadelphia, Pennsylvania, have invented for avoiding the production of these eddycertain Improvements in Dynamo-Electric currents and the consequent heating of the Machines and Motors, of which the following core. is a specification. In the accompanying drawings, A is the ar- The object of my invention is to so 0011- mature-shaft, which in the case of a ring-arstruot an armature for a dynamo-electric mamature carries a suitable spider, a, on which IO chine or electric motor as to lessen the liaare mounted the ring-plates P, constituting 6o bility of the heating of the iron in the polethe core of the armature. In the case of a pieces and to increase the efficiency of the drum-armature the shaft carries the sleeve (0, machine. on which are mounted the plates P, which go In the accompanying drawings, Figure 1 is a to make up the core. In eithercase the plates 15 longitudinal elevation of my improved arma- P or P have around their peripheries proture with a portion in section. Fig. 2 is an jecting teeth 19, which when the plates are end view of a ringarmature in accordance put together constitute polar connections or with my invention, and showing some of the teeth 011 the armature-core. In the spaces heconduetors in sections; and Fig. 3 is a sectween'these polar projections or teeth are 20 tional View of admin-armature embodyingmy wound the insulated conductors L, the termi- 7o improvements. nals of which are suitably connected to a As will be seen from the foregoing illuscommutator C, Fig. 1. Around the armature trations, my invention may be applied either thus formed I then place a divided sheath of to a ring-armature or a drum-armature. In iron,which, as a matter of constructional con 2 5 either case the iron core is formed of a series venience, I make of insulated iron wire, S, of juxtaposed iron plates either in the form wound circui'nferentially over the armature of rings or disks and with the electrical con throughout the length of the polar projecductors wound over the core. It is now a tions. This divided iron sheath may, if degenerally-accepted theory that it is rather an sired, be in magnetic contact with the polar o objection than an advantage to provide these projections of the armature-core; but I do not plates or disks which go to form the armaregard actual contact as essential. ture with. projecting teeth constituting polar IVhen the machine is in operation, I find projections,although. it was for some time the that by the presence of this divided iron custom to construct the armature-cores with sheath the heating of the core is greatly less- 3 5 these projections or teeth and to wind the inened, if not entirely prevented, and the efsulated conductors in the spaces between iiciency of the machine considerably inthese projections. The objection which has creased. In other words, the presence of this been made to the use of projections is that divided iron sheath between the polar prothey tend to produce eddy-currents in the jections and the iron core and the poles of 40 iron field-pieces, particularly as each polar the field-magnet has the eitect of almost en- 0 projection leaves the pole-pieces of the fieldtirely getting rid of the eddy-currents which magnet in the revolution of the armature. usually follow from the use of the polar pro- Owing to these eddy-currents the iron core of jections on the armature-core. the field-magnets becomes heated and the ef- I claim as my invention 45 ficiency of the machine considerably lessened. 1. An armature-core for a dynamo-electric 5 I believe, however, that these polar projecmachine or electric motor, having an iron core tions on the armature-core, by reducing the with polar projections or teeth and a divided resistance of the air-space, possess certain adiron sheath around the outside of the armavantages which would increase the efficiency ture throughout the length or part of the 5oof the machine if the production of these length of the polar projections. 10o

2. An armature for a dynamo-electric machine or electric motor, having a divided iron core with polar projections and a divided iron sheath composed of iron wire wrapped around 5 the armature circumferentialiy throughout the length or part of the length of the polar projections.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CARL O. O. BILLBERG.

Witnesses: v

HENRY HOWSON, HARRY SMITH. 

